) Class.forName(fullName, true,
context.getClassLoader());
c = clazz.getConstructor(CONSTRUCTOR_PARAMS);
c.setAccessible(true);
constructors.put(fullName, c);
}
return c.newInstance(context, attrs);
} catch (Exception e) {
throw new RuntimeException("Could not inflate Behavior subclass " + fullName, e);
}
}
LayoutParams getResolvedLayoutParams(View child) {
final LayoutParams result = (LayoutParams) child.getLayoutParams();
if (!result.mBehaviorResolved) {
Class childClass = child.getClass();
DefaultBehavior defaultBehavior = null;
while (childClass != null &&
(defaultBehavior = childClass.getAnnotation(DefaultBehavior.class)) == null) {
childClass = childClass.getSuperclass();
}
if (defaultBehavior != null) {
try {
result.setBehavior(
defaultBehavior.value().getDeclaredConstructor().newInstance());
} catch (Exception e) {
Log.e(TAG, "Default behavior class " + defaultBehavior.value().getName() +
" could not be instantiated. Did you forget a default constructor?", e);
}
}
result.mBehaviorResolved = true;
}
return result;
}
private void prepareChildren() {
mDependencySortedChildren.clear();
mChildDag.clear();
for (int i = 0, count = getChildCount(); i < count; i++) {
final View view = getChildAt(i);
final LayoutParams lp = getResolvedLayoutParams(view);
lp.findAnchorView(this, view);
mChildDag.addNode(view);
// Now iterate again over the other children, adding any dependencies to the graph
for (int j = 0; j < count; j++) {
if (j == i) {
continue;
}
final View other = getChildAt(j);
if (lp.dependsOn(this, view, other)) {
if (!mChildDag.contains(other)) {
// Make sure that the other node is added
mChildDag.addNode(other);
}
// Now add the dependency to the graph
mChildDag.addEdge(other, view);
}
}
}
// Finally add the sorted graph list to our list
mDependencySortedChildren.addAll(mChildDag.getSortedList());
// We also need to reverse the result since we want the start of the list to contain
// Views which have no dependencies, then dependent views after that
Collections.reverse(mDependencySortedChildren);
}
/**
* Retrieve the transformed bounding rect of an arbitrary descendant view.
* This does not need to be a direct child.
*
* @param descendant descendant view to reference
* @param out rect to set to the bounds of the descendant view
*/
void getDescendantRect(View descendant, Rect out) {
ViewGroupUtils.getDescendantRect(this, descendant, out);
}
@Override
protected int getSuggestedMinimumWidth() {
return Math.max(super.getSuggestedMinimumWidth(), getPaddingLeft() + getPaddingRight());
}
@Override
protected int getSuggestedMinimumHeight() {
return Math.max(super.getSuggestedMinimumHeight(), getPaddingTop() + getPaddingBottom());
}
/**
* Called to measure each individual child view unless a
* {@link CoordinatorLayout.Behavior Behavior} is present. The Behavior may choose to delegate
* child measurement to this method.
*
* @param child the child to measure
* @param parentWidthMeasureSpec the width requirements for this view
* @param widthUsed extra space that has been used up by the parent
* horizontally (possibly by other children of the parent)
* @param parentHeightMeasureSpec the height requirements for this view
* @param heightUsed extra space that has been used up by the parent
* vertically (possibly by other children of the parent)
*/
public void onMeasureChild(View child, int parentWidthMeasureSpec, int widthUsed,
int parentHeightMeasureSpec, int heightUsed) {
measureChildWithMargins(child, parentWidthMeasureSpec, widthUsed,
parentHeightMeasureSpec, heightUsed);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
prepareChildren();
ensurePreDrawListener();
final int paddingLeft = getPaddingLeft();
final int paddingTop = getPaddingTop();
final int paddingRight = getPaddingRight();
final int paddingBottom = getPaddingBottom();
final int layoutDirection = ViewCompat.getLayoutDirection(this);
final boolean isRtl = layoutDirection == ViewCompat.LAYOUT_DIRECTION_RTL;
final int widthMode = MeasureSpec.getMode(widthMeasureSpec);
final int widthSize = MeasureSpec.getSize(widthMeasureSpec);
final int heightMode = MeasureSpec.getMode(heightMeasureSpec);
final int heightSize = MeasureSpec.getSize(heightMeasureSpec);
final int widthPadding = paddingLeft + paddingRight;
final int heightPadding = paddingTop + paddingBottom;
int widthUsed = getSuggestedMinimumWidth();
int heightUsed = getSuggestedMinimumHeight();
int childState = 0;
final boolean applyInsets = mLastInsets != null && ViewCompat.getFitsSystemWindows(this);
final int childCount = mDependencySortedChildren.size();
for (int i = 0; i < childCount; i++) {
final View child = mDependencySortedChildren.get(i);
if (child.getVisibility() == GONE) {
// If the child is GONE, skip...
continue;
}
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
int keylineWidthUsed = 0;
if (lp.keyline >= 0 && widthMode != MeasureSpec.UNSPECIFIED) {
final int keylinePos = getKeyline(lp.keyline);
final int keylineGravity = GravityCompat.getAbsoluteGravity(
resolveKeylineGravity(lp.gravity), layoutDirection)
& Gravity.HORIZONTAL_GRAVITY_MASK;
if ((keylineGravity == Gravity.LEFT && !isRtl)
|| (keylineGravity == Gravity.RIGHT && isRtl)) {
keylineWidthUsed = Math.max(0, widthSize - paddingRight - keylinePos);
} else if ((keylineGravity == Gravity.RIGHT && !isRtl)
|| (keylineGravity == Gravity.LEFT && isRtl)) {
keylineWidthUsed = Math.max(0, keylinePos - paddingLeft);
}
}
int childWidthMeasureSpec = widthMeasureSpec;
int childHeightMeasureSpec = heightMeasureSpec;
if (applyInsets && !ViewCompat.getFitsSystemWindows(child)) {
// We're set to handle insets but this child isn't, so we will measure the
// child as if there are no insets
final int horizInsets = mLastInsets.getSystemWindowInsetLeft()
+ mLastInsets.getSystemWindowInsetRight();
final int vertInsets = mLastInsets.getSystemWindowInsetTop()
+ mLastInsets.getSystemWindowInsetBottom();
childWidthMeasureSpec = MeasureSpec.makeMeasureSpec(
widthSize - horizInsets, widthMode);
childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(
heightSize - vertInsets, heightMode);
}
final Behavior b = lp.getBehavior();
if (b == null || !b.onMeasureChild(this, child, childWidthMeasureSpec, keylineWidthUsed,
childHeightMeasureSpec, 0)) {
onMeasureChild(child, childWidthMeasureSpec, keylineWidthUsed,
childHeightMeasureSpec, 0);
}
widthUsed = Math.max(widthUsed, widthPadding + child.getMeasuredWidth() +
lp.leftMargin + lp.rightMargin);
heightUsed = Math.max(heightUsed, heightPadding + child.getMeasuredHeight() +
lp.topMargin + lp.bottomMargin);
childState = View.combineMeasuredStates(childState, child.getMeasuredState());
}
final int width = View.resolveSizeAndState(widthUsed, widthMeasureSpec,
childState & View.MEASURED_STATE_MASK);
final int height = View.resolveSizeAndState(heightUsed, heightMeasureSpec,
childState << View.MEASURED_HEIGHT_STATE_SHIFT);
setMeasuredDimension(width, height);
}
private WindowInsetsCompat dispatchApplyWindowInsetsToBehaviors(WindowInsetsCompat insets) {
if (insets.isConsumed()) {
return insets;
}
for (int i = 0, z = getChildCount(); i < z; i++) {
final View child = getChildAt(i);
if (ViewCompat.getFitsSystemWindows(child)) {
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
final Behavior b = lp.getBehavior();
if (b != null) {
// If the view has a behavior, let it try first
insets = b.onApplyWindowInsets(this, child, insets);
if (insets.isConsumed()) {
// If it consumed the insets, break
break;
}
}
}
}
return insets;
}
/**
* Called to lay out each individual child view unless a
* {@link CoordinatorLayout.Behavior Behavior} is present. The Behavior may choose to
* delegate child measurement to this method.
*
* @param child child view to lay out
* @param layoutDirection the resolved layout direction for the CoordinatorLayout, such as
* {@link ViewCompat#LAYOUT_DIRECTION_LTR} or
* {@link ViewCompat#LAYOUT_DIRECTION_RTL}.
*/
public void onLayoutChild(View child, int layoutDirection) {
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
if (lp.checkAnchorChanged()) {
throw new IllegalStateException("An anchor may not be changed after CoordinatorLayout"
+ " measurement begins before layout is complete.");
}
if (lp.mAnchorView != null) {
layoutChildWithAnchor(child, lp.mAnchorView, layoutDirection);
} else if (lp.keyline >= 0) {
layoutChildWithKeyline(child, lp.keyline, layoutDirection);
} else {
layoutChild(child, layoutDirection);
}
}
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
final int layoutDirection = ViewCompat.getLayoutDirection(this);
final int childCount = mDependencySortedChildren.size();
for (int i = 0; i < childCount; i++) {
final View child = mDependencySortedChildren.get(i);
if (child.getVisibility() == GONE) {
// If the child is GONE, skip...
continue;
}
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
final Behavior behavior = lp.getBehavior();
if (behavior == null || !behavior.onLayoutChild(this, child, layoutDirection)) {
onLayoutChild(child, layoutDirection);
}
}
}
@Override
public void onDraw(Canvas c) {
super.onDraw(c);
if (mDrawStatusBarBackground && mStatusBarBackground != null) {
final int inset = mLastInsets != null ? mLastInsets.getSystemWindowInsetTop() : 0;
if (inset > 0) {
mStatusBarBackground.setBounds(0, 0, getWidth(), inset);
mStatusBarBackground.draw(c);
}
}
}
@Override
public void setFitsSystemWindows(boolean fitSystemWindows) {
super.setFitsSystemWindows(fitSystemWindows);
setupForInsets();
}
/**
* Mark the last known child position rect for the given child view.
* This will be used when checking if a child view's position has changed between frames.
* The rect used here should be one returned by
* {@link #getChildRect(android.view.View, boolean, android.graphics.Rect)}, with translation
* disabled.
*
* @param child child view to set for
* @param r rect to set
*/
void recordLastChildRect(View child, Rect r) {
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
lp.setLastChildRect(r);
}
/**
* Get the last known child rect recorded by
* {@link #recordLastChildRect(android.view.View, android.graphics.Rect)}.
*
* @param child child view to retrieve from
* @param out rect to set to the outpur values
*/
void getLastChildRect(View child, Rect out) {
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
out.set(lp.getLastChildRect());
}
/**
* Get the position rect for the given child. If the child has currently requested layout
* or has a visibility of GONE.
*
* @param child child view to check
* @param transform true to include transformation in the output rect, false to
* only account for the base position
* @param out rect to set to the output values
*/
void getChildRect(View child, boolean transform, Rect out) {
if (child.isLayoutRequested() || child.getVisibility() == View.GONE) {
out.setEmpty();
return;
}
if (transform) {
getDescendantRect(child, out);
} else {
out.set(child.getLeft(), child.getTop(), child.getRight(), child.getBottom());
}
}
private void getDesiredAnchoredChildRectWithoutConstraints(View child, int layoutDirection,
Rect anchorRect, Rect out, LayoutParams lp, int childWidth, int childHeight) {
final int absGravity = GravityCompat.getAbsoluteGravity(
resolveAnchoredChildGravity(lp.gravity), layoutDirection);
final int absAnchorGravity = GravityCompat.getAbsoluteGravity(
resolveGravity(lp.anchorGravity),
layoutDirection);
final int hgrav = absGravity & Gravity.HORIZONTAL_GRAVITY_MASK;
final int vgrav = absGravity & Gravity.VERTICAL_GRAVITY_MASK;
final int anchorHgrav = absAnchorGravity & Gravity.HORIZONTAL_GRAVITY_MASK;
final int anchorVgrav = absAnchorGravity & Gravity.VERTICAL_GRAVITY_MASK;
int left;
int top;
// Align to the anchor. This puts us in an assumed right/bottom child view gravity.
// If this is not the case we will subtract out the appropriate portion of
// the child size below.
switch (anchorHgrav) {
default:
case Gravity.LEFT:
left = anchorRect.left;
break;
case Gravity.RIGHT:
left = anchorRect.right;
break;
case Gravity.CENTER_HORIZONTAL:
left = anchorRect.left + anchorRect.width() / 2;
break;
}
switch (anchorVgrav) {
default:
case Gravity.TOP:
top = anchorRect.top;
break;
case Gravity.BOTTOM:
top = anchorRect.bottom;
break;
case Gravity.CENTER_VERTICAL:
top = anchorRect.top + anchorRect.height() / 2;
break;
}
// Offset by the child view's gravity itself. The above assumed right/bottom gravity.
switch (hgrav) {
default:
case Gravity.LEFT:
left -= childWidth;
break;
case Gravity.RIGHT:
// Do nothing, we're already in position.
break;
case Gravity.CENTER_HORIZONTAL:
left -= childWidth / 2;
break;
}
switch (vgrav) {
default:
case Gravity.TOP:
top -= childHeight;
break;
case Gravity.BOTTOM:
// Do nothing, we're already in position.
break;
case Gravity.CENTER_VERTICAL:
top -= childHeight / 2;
break;
}
out.set(left, top, left + childWidth, top + childHeight);
}
private void constrainChildRect(LayoutParams lp, Rect out, int childWidth, int childHeight) {
final int width = getWidth();
final int height = getHeight();
// Obey margins and padding
int left = Math.max(getPaddingLeft() + lp.leftMargin,
Math.min(out.left,
width - getPaddingRight() - childWidth - lp.rightMargin));
int top = Math.max(getPaddingTop() + lp.topMargin,
Math.min(out.top,
height - getPaddingBottom() - childHeight - lp.bottomMargin));
out.set(left, top, left + childWidth, top + childHeight);
}
/**
* Calculate the desired child rect relative to an anchor rect, respecting both
* gravity and anchorGravity.
*
* @param child child view to calculate a rect for
* @param layoutDirection the desired layout direction for the CoordinatorLayout
* @param anchorRect rect in CoordinatorLayout coordinates of the anchor view area
* @param out rect to set to the output values
*/
void getDesiredAnchoredChildRect(View child, int layoutDirection, Rect anchorRect, Rect out) {
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
final int childWidth = child.getMeasuredWidth();
final int childHeight = child.getMeasuredHeight();
getDesiredAnchoredChildRectWithoutConstraints(child, layoutDirection, anchorRect, out, lp,
childWidth, childHeight);
constrainChildRect(lp, out, childWidth, childHeight);
}
/**
* CORE ASSUMPTION: anchor has been laid out by the time this is called for a given child view.
*
* @param child child to lay out
* @param anchor view to anchor child relative to; already laid out.
* @param layoutDirection ViewCompat constant for layout direction
*/
private void layoutChildWithAnchor(View child, View anchor, int layoutDirection) {
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
final Rect anchorRect = acquireTempRect();
final Rect childRect = acquireTempRect();
try {
getDescendantRect(anchor, anchorRect);
getDesiredAnchoredChildRect(child, layoutDirection, anchorRect, childRect);
child.layout(childRect.left, childRect.top, childRect.right, childRect.bottom);
} finally {
releaseTempRect(anchorRect);
releaseTempRect(childRect);
}
}
/**
* Lay out a child view with respect to a keyline.
*
* The keyline represents a horizontal offset from the unpadded starting edge of
* the CoordinatorLayout. The child's gravity will affect how it is positioned with
* respect to the keyline.
*
* @param child child to lay out
* @param keyline offset from the starting edge in pixels of the keyline to align with
* @param layoutDirection ViewCompat constant for layout direction
*/
private void layoutChildWithKeyline(View child, int keyline, int layoutDirection) {
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
final int absGravity = GravityCompat.getAbsoluteGravity(
resolveKeylineGravity(lp.gravity), layoutDirection);
final int hgrav = absGravity & Gravity.HORIZONTAL_GRAVITY_MASK;
final int vgrav = absGravity & Gravity.VERTICAL_GRAVITY_MASK;
final int width = getWidth();
final int height = getHeight();
final int childWidth = child.getMeasuredWidth();
final int childHeight = child.getMeasuredHeight();
if (layoutDirection == ViewCompat.LAYOUT_DIRECTION_RTL) {
keyline = width - keyline;
}
int left = getKeyline(keyline) - childWidth;
int top = 0;
switch (hgrav) {
default:
case Gravity.LEFT:
// Nothing to do.
break;
case Gravity.RIGHT:
left += childWidth;
break;
case Gravity.CENTER_HORIZONTAL:
left += childWidth / 2;
break;
}
switch (vgrav) {
default:
case Gravity.TOP:
// Do nothing, we're already in position.
break;
case Gravity.BOTTOM:
top += childHeight;
break;
case Gravity.CENTER_VERTICAL:
top += childHeight / 2;
break;
}
// Obey margins and padding
left = Math.max(getPaddingLeft() + lp.leftMargin,
Math.min(left,
width - getPaddingRight() - childWidth - lp.rightMargin));
top = Math.max(getPaddingTop() + lp.topMargin,
Math.min(top,
height - getPaddingBottom() - childHeight - lp.bottomMargin));
child.layout(left, top, left + childWidth, top + childHeight);
}
/**
* Lay out a child view with no special handling. This will position the child as
* if it were within a FrameLayout or similar simple frame.
*
* @param child child view to lay out
* @param layoutDirection ViewCompat constant for the desired layout direction
*/
private void layoutChild(View child, int layoutDirection) {
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
final Rect parent = acquireTempRect();
parent.set(getPaddingLeft() + lp.leftMargin,
getPaddingTop() + lp.topMargin,
getWidth() - getPaddingRight() - lp.rightMargin,
getHeight() - getPaddingBottom() - lp.bottomMargin);
if (mLastInsets != null && ViewCompat.getFitsSystemWindows(this)
&& !ViewCompat.getFitsSystemWindows(child)) {
// If we're set to handle insets but this child isn't, then it has been measured as
// if there are no insets. We need to lay it out to match.
parent.left += mLastInsets.getSystemWindowInsetLeft();
parent.top += mLastInsets.getSystemWindowInsetTop();
parent.right -= mLastInsets.getSystemWindowInsetRight();
parent.bottom -= mLastInsets.getSystemWindowInsetBottom();
}
final Rect out = acquireTempRect();
GravityCompat.apply(resolveGravity(lp.gravity), child.getMeasuredWidth(),
child.getMeasuredHeight(), parent, out, layoutDirection);
child.layout(out.left, out.top, out.right, out.bottom);
releaseTempRect(parent);
releaseTempRect(out);
}
/**
* Return the given gravity value, but if either or both of the axes doesn't have any gravity
* specified, the default value (start or top) is specified. This should be used for children
* that are not anchored to another view or a keyline.
*/
private static int resolveGravity(int gravity) {
if ((gravity & Gravity.HORIZONTAL_GRAVITY_MASK) == Gravity.NO_GRAVITY) {
gravity |= GravityCompat.START;
}
if ((gravity & Gravity.VERTICAL_GRAVITY_MASK) == Gravity.NO_GRAVITY) {
gravity |= Gravity.TOP;
}
return gravity;
}
/**
* Return the given gravity value or the default if the passed value is NO_GRAVITY.
* This should be used for children that are positioned relative to a keyline.
*/
private static int resolveKeylineGravity(int gravity) {
return gravity == Gravity.NO_GRAVITY ? GravityCompat.END | Gravity.TOP : gravity;
}
/**
* Return the given gravity value or the default if the passed value is NO_GRAVITY.
* This should be used for children that are anchored to another view.
*/
private static int resolveAnchoredChildGravity(int gravity) {
return gravity == Gravity.NO_GRAVITY ? Gravity.CENTER : gravity;
}
@Override
protected boolean drawChild(Canvas canvas, View child, long drawingTime) {
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
if (lp.mBehavior != null) {
final float scrimAlpha = lp.mBehavior.getScrimOpacity(this, child);
if (scrimAlpha > 0f) {
if (mScrimPaint == null) {
mScrimPaint = new Paint();
}
mScrimPaint.setColor(lp.mBehavior.getScrimColor(this, child));
mScrimPaint.setAlpha(MathUtils.clamp(Math.round(255 * scrimAlpha), 0, 255));
final int saved = canvas.save();
if (child.isOpaque()) {
// If the child is opaque, there is no need to draw behind it so we'll inverse
// clip the canvas
canvas.clipRect(child.getLeft(), child.getTop(), child.getRight(),
child.getBottom(), Region.Op.DIFFERENCE);
}
// Now draw the rectangle for the scrim
canvas.drawRect(getPaddingLeft(), getPaddingTop(),
getWidth() - getPaddingRight(), getHeight() - getPaddingBottom(),
mScrimPaint);
canvas.restoreToCount(saved);
}
}
return super.drawChild(canvas, child, drawingTime);
}
/**
* Dispatch any dependent view changes to the relevant {@link Behavior} instances.
*
* Usually run as part of the pre-draw step when at least one child view has a reported
* dependency on another view. This allows CoordinatorLayout to account for layout
* changes and animations that occur outside of the normal layout pass.
*
* It can also be ran as part of the nested scrolling dispatch to ensure that any offsetting
* is completed within the correct coordinate window.
*
* The offsetting behavior implemented here does not store the computed offset in
* the LayoutParams; instead it expects that the layout process will always reconstruct
* the proper positioning.
*
* @param type the type of event which has caused this call
*/
final void onChildViewsChanged(@DispatchChangeEvent final int type) {
final int layoutDirection = ViewCompat.getLayoutDirection(this);
final int childCount = mDependencySortedChildren.size();
final Rect inset = acquireTempRect();
final Rect drawRect = acquireTempRect();
final Rect lastDrawRect = acquireTempRect();
for (int i = 0; i < childCount; i++) {
final View child = mDependencySortedChildren.get(i);
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
if (type == EVENT_PRE_DRAW && child.getVisibility() == View.GONE) {
// Do not try to update GONE child views in pre draw updates.
continue;
}
// Check child views before for anchor
for (int j = 0; j < i; j++) {
final View checkChild = mDependencySortedChildren.get(j);
if (lp.mAnchorDirectChild == checkChild) {
offsetChildToAnchor(child, layoutDirection);
}
}
// Get the current draw rect of the view
getChildRect(child, true, drawRect);
// Accumulate inset sizes
if (lp.insetEdge != Gravity.NO_GRAVITY && !drawRect.isEmpty()) {
final int absInsetEdge = GravityCompat.getAbsoluteGravity(
lp.insetEdge, layoutDirection);
switch (absInsetEdge & Gravity.VERTICAL_GRAVITY_MASK) {
case Gravity.TOP:
inset.top = Math.max(inset.top, drawRect.bottom);
break;
case Gravity.BOTTOM:
inset.bottom = Math.max(inset.bottom, getHeight() - drawRect.top);
break;
}
switch (absInsetEdge & Gravity.HORIZONTAL_GRAVITY_MASK) {
case Gravity.LEFT:
inset.left = Math.max(inset.left, drawRect.right);
break;
case Gravity.RIGHT:
inset.right = Math.max(inset.right, getWidth() - drawRect.left);
break;
}
}
// Dodge inset edges if necessary
if (lp.dodgeInsetEdges != Gravity.NO_GRAVITY && child.getVisibility() == View.VISIBLE) {
offsetChildByInset(child, inset, layoutDirection);
}
if (type != EVENT_VIEW_REMOVED) {
// Did it change? if not continue
getLastChildRect(child, lastDrawRect);
if (lastDrawRect.equals(drawRect)) {
continue;
}
recordLastChildRect(child, drawRect);
}
// Update any behavior-dependent views for the change
for (int j = i + 1; j < childCount; j++) {
final View checkChild = mDependencySortedChildren.get(j);
final LayoutParams checkLp = (LayoutParams) checkChild.getLayoutParams();
final Behavior b = checkLp.getBehavior();
if (b != null && b.layoutDependsOn(this, checkChild, child)) {
if (type == EVENT_PRE_DRAW && checkLp.getChangedAfterNestedScroll()) {
// If this is from a pre-draw and we have already been changed
// from a nested scroll, skip the dispatch and reset the flag
checkLp.resetChangedAfterNestedScroll();
continue;
}
final boolean handled;
switch (type) {
case EVENT_VIEW_REMOVED:
// EVENT_VIEW_REMOVED means that we need to dispatch
// onDependentViewRemoved() instead
b.onDependentViewRemoved(this, checkChild, child);
handled = true;
break;
default:
// Otherwise we dispatch onDependentViewChanged()
handled = b.onDependentViewChanged(this, checkChild, child);
break;
}
if (type == EVENT_NESTED_SCROLL) {
// If this is from a nested scroll, set the flag so that we may skip
// any resulting onPreDraw dispatch (if needed)
checkLp.setChangedAfterNestedScroll(handled);
}
}
}
}
releaseTempRect(inset);
releaseTempRect(drawRect);
releaseTempRect(lastDrawRect);
}
private void offsetChildByInset(final View child, final Rect inset, final int layoutDirection) {
if (!ViewCompat.isLaidOut(child)) {
// The view has not been laid out yet, so we can't obtain its bounds.
return;
}
if (child.getWidth() <= 0 || child.getHeight() <= 0) {
// Bounds are empty so there is nothing to dodge against, skip...
return;
}
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
final Behavior behavior = lp.getBehavior();
final Rect dodgeRect = acquireTempRect();
final Rect bounds = acquireTempRect();
bounds.set(child.getLeft(), child.getTop(), child.getRight(), child.getBottom());
if (behavior != null && behavior.getInsetDodgeRect(this, child, dodgeRect)) {
// Make sure that the rect is within the view's bounds
if (!bounds.contains(dodgeRect)) {
throw new IllegalArgumentException("Rect should be within the child's bounds."
+ " Rect:" + dodgeRect.toShortString()
+ " | Bounds:" + bounds.toShortString());
}
} else {
dodgeRect.set(bounds);
}
// We can release the bounds rect now
releaseTempRect(bounds);
if (dodgeRect.isEmpty()) {
// Rect is empty so there is nothing to dodge against, skip...
releaseTempRect(dodgeRect);
return;
}
final int absDodgeInsetEdges = GravityCompat.getAbsoluteGravity(lp.dodgeInsetEdges,
layoutDirection);
boolean offsetY = false;
if ((absDodgeInsetEdges & Gravity.TOP) == Gravity.TOP) {
int distance = dodgeRect.top - lp.topMargin - lp.mInsetOffsetY;
if (distance < inset.top) {
setInsetOffsetY(child, inset.top - distance);
offsetY = true;
}
}
if ((absDodgeInsetEdges & Gravity.BOTTOM) == Gravity.BOTTOM) {
int distance = getHeight() - dodgeRect.bottom - lp.bottomMargin + lp.mInsetOffsetY;
if (distance < inset.bottom) {
setInsetOffsetY(child, distance - inset.bottom);
offsetY = true;
}
}
if (!offsetY) {
setInsetOffsetY(child, 0);
}
boolean offsetX = false;
if ((absDodgeInsetEdges & Gravity.LEFT) == Gravity.LEFT) {
int distance = dodgeRect.left - lp.leftMargin - lp.mInsetOffsetX;
if (distance < inset.left) {
setInsetOffsetX(child, inset.left - distance);
offsetX = true;
}
}
if ((absDodgeInsetEdges & Gravity.RIGHT) == Gravity.RIGHT) {
int distance = getWidth() - dodgeRect.right - lp.rightMargin + lp.mInsetOffsetX;
if (distance < inset.right) {
setInsetOffsetX(child, distance - inset.right);
offsetX = true;
}
}
if (!offsetX) {
setInsetOffsetX(child, 0);
}
releaseTempRect(dodgeRect);
}
private void setInsetOffsetX(View child, int offsetX) {
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
if (lp.mInsetOffsetX != offsetX) {
final int dx = offsetX - lp.mInsetOffsetX;
ViewCompat.offsetLeftAndRight(child, dx);
lp.mInsetOffsetX = offsetX;
}
}
private void setInsetOffsetY(View child, int offsetY) {
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
if (lp.mInsetOffsetY != offsetY) {
final int dy = offsetY - lp.mInsetOffsetY;
ViewCompat.offsetTopAndBottom(child, dy);
lp.mInsetOffsetY = offsetY;
}
}
/**
* Allows the caller to manually dispatch
* {@link Behavior#onDependentViewChanged(CoordinatorLayout, View, View)} to the associated
* {@link Behavior} instances of views which depend on the provided {@link View}.
*
* You should not normally need to call this method as the it will be automatically done
* when the view has changed.
*
* @param view the View to find dependents of to dispatch the call.
*/
public void dispatchDependentViewsChanged(View view) {
final List dependents = mChildDag.getIncomingEdges(view);
if (dependents != null && !dependents.isEmpty()) {
for (int i = 0; i < dependents.size(); i++) {
final View child = dependents.get(i);
CoordinatorLayout.LayoutParams lp = (CoordinatorLayout.LayoutParams)
child.getLayoutParams();
CoordinatorLayout.Behavior b = lp.getBehavior();
if (b != null) {
b.onDependentViewChanged(this, child, view);
}
}
}
}
/**
* Returns the list of views which the provided view depends on. Do not store this list as its
* contents may not be valid beyond the caller.
*
* @param child the view to find dependencies for.
*
* @return the list of views which {@code child} depends on.
*/
@NonNull
public List getDependencies(@NonNull View child) {
final List dependencies = mChildDag.getOutgoingEdges(child);
mTempDependenciesList.clear();
if (dependencies != null) {
mTempDependenciesList.addAll(dependencies);
}
return mTempDependenciesList;
}
/**
* Returns the list of views which depend on the provided view. Do not store this list as its
* contents may not be valid beyond the caller.
*
* @param child the view to find dependents of.
*
* @return the list of views which depend on {@code child}.
*/
@NonNull
public List getDependents(@NonNull View child) {
final List edges = mChildDag.getIncomingEdges(child);
mTempDependenciesList.clear();
if (edges != null) {
mTempDependenciesList.addAll(edges);
}
return mTempDependenciesList;
}
@VisibleForTesting
final List getDependencySortedChildren() {
prepareChildren();
return Collections.unmodifiableList(mDependencySortedChildren);
}
/**
* Add or remove the pre-draw listener as necessary.
*/
void ensurePreDrawListener() {
boolean hasDependencies = false;
final int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
final View child = getChildAt(i);
if (hasDependencies(child)) {
hasDependencies = true;
break;
}
}
if (hasDependencies != mNeedsPreDrawListener) {
if (hasDependencies) {
addPreDrawListener();
} else {
removePreDrawListener();
}
}
}
/**
* Check if the given child has any layout dependencies on other child views.
*/
private boolean hasDependencies(View child) {
return mChildDag.hasOutgoingEdges(child);
}
/**
* Add the pre-draw listener if we're attached to a window and mark that we currently
* need it when attached.
*/
void addPreDrawListener() {
if (mIsAttachedToWindow) {
// Add the listener
if (mOnPreDrawListener == null) {
mOnPreDrawListener = new OnPreDrawListener();
}
final ViewTreeObserver vto = getViewTreeObserver();
vto.addOnPreDrawListener(mOnPreDrawListener);
}
// Record that we need the listener regardless of whether or not we're attached.
// We'll add the real listener when we become attached.
mNeedsPreDrawListener = true;
}
/**
* Remove the pre-draw listener if we're attached to a window and mark that we currently
* do not need it when attached.
*/
void removePreDrawListener() {
if (mIsAttachedToWindow) {
if (mOnPreDrawListener != null) {
final ViewTreeObserver vto = getViewTreeObserver();
vto.removeOnPreDrawListener(mOnPreDrawListener);
}
}
mNeedsPreDrawListener = false;
}
/**
* Adjust the child left, top, right, bottom rect to the correct anchor view position,
* respecting gravity and anchor gravity.
*
* Note that child translation properties are ignored in this process, allowing children
* to be animated away from their anchor. However, if the anchor view is animated,
* the child will be offset to match the anchor's translated position.
*/
void offsetChildToAnchor(View child, int layoutDirection) {
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
if (lp.mAnchorView != null) {
final Rect anchorRect = acquireTempRect();
final Rect childRect = acquireTempRect();
final Rect desiredChildRect = acquireTempRect();
getDescendantRect(lp.mAnchorView, anchorRect);
getChildRect(child, false, childRect);
int childWidth = child.getMeasuredWidth();
int childHeight = child.getMeasuredHeight();
getDesiredAnchoredChildRectWithoutConstraints(child, layoutDirection, anchorRect,
desiredChildRect, lp, childWidth, childHeight);
boolean changed = desiredChildRect.left != childRect.left ||
desiredChildRect.top != childRect.top;
constrainChildRect(lp, desiredChildRect, childWidth, childHeight);
final int dx = desiredChildRect.left - childRect.left;
final int dy = desiredChildRect.top - childRect.top;
if (dx != 0) {
ViewCompat.offsetLeftAndRight(child, dx);
}
if (dy != 0) {
ViewCompat.offsetTopAndBottom(child, dy);
}
if (changed) {
// If we have needed to move, make sure to notify the child's Behavior
final Behavior b = lp.getBehavior();
if (b != null) {
b.onDependentViewChanged(this, child, lp.mAnchorView);
}
}
releaseTempRect(anchorRect);
releaseTempRect(childRect);
releaseTempRect(desiredChildRect);
}
}
/**
* Check if a given point in the CoordinatorLayout's coordinates are within the view bounds
* of the given direct child view.
*
* @param child child view to test
* @param x X coordinate to test, in the CoordinatorLayout's coordinate system
* @param y Y coordinate to test, in the CoordinatorLayout's coordinate system
* @return true if the point is within the child view's bounds, false otherwise
*/
public boolean isPointInChildBounds(View child, int x, int y) {
final Rect r = acquireTempRect();
getDescendantRect(child, r);
try {
return r.contains(x, y);
} finally {
releaseTempRect(r);
}
}
/**
* Check whether two views overlap each other. The views need to be descendants of this
* {@link CoordinatorLayout} in the view hierarchy.
*
* @param first first child view to test
* @param second second child view to test
* @return true if both views are visible and overlap each other
*/
public boolean doViewsOverlap(View first, View second) {
if (first.getVisibility() == VISIBLE && second.getVisibility() == VISIBLE) {
final Rect firstRect = acquireTempRect();
getChildRect(first, first.getParent() != this, firstRect);
final Rect secondRect = acquireTempRect();
getChildRect(second, second.getParent() != this, secondRect);
try {
return !(firstRect.left > secondRect.right || firstRect.top > secondRect.bottom
|| firstRect.right < secondRect.left || firstRect.bottom < secondRect.top);
} finally {
releaseTempRect(firstRect);
releaseTempRect(secondRect);
}
}
return false;
}
@Override
public LayoutParams generateLayoutParams(AttributeSet attrs) {
return new LayoutParams(getContext(), attrs);
}
@Override
protected LayoutParams generateLayoutParams(ViewGroup.LayoutParams p) {
if (p instanceof LayoutParams) {
return new LayoutParams((LayoutParams) p);
} else if (p instanceof MarginLayoutParams) {
return new LayoutParams((MarginLayoutParams) p);
}
return new LayoutParams(p);
}
@Override
protected LayoutParams generateDefaultLayoutParams() {
return new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
}
@Override
protected boolean checkLayoutParams(ViewGroup.LayoutParams p) {
return p instanceof LayoutParams && super.checkLayoutParams(p);
}
@Override
public boolean onStartNestedScroll(View child, View target, int nestedScrollAxes) {
return onStartNestedScroll(child, target, nestedScrollAxes, ViewCompat.TYPE_TOUCH);
}
@Override
public boolean onStartNestedScroll(View child, View target, int axes, int type) {
boolean handled = false;
final int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
final View view = getChildAt(i);
if (view.getVisibility() == View.GONE) {
// If it's GONE, don't dispatch
continue;
}
final LayoutParams lp = (LayoutParams) view.getLayoutParams();
final Behavior viewBehavior = lp.getBehavior();
if (viewBehavior != null) {
final boolean accepted = viewBehavior.onStartNestedScroll(this, view, child,
target, axes, type);
handled |= accepted;
lp.setNestedScrollAccepted(type, accepted);
} else {
lp.setNestedScrollAccepted(type, false);
}
}
return handled;
}
@Override
public void onNestedScrollAccepted(View child, View target, int nestedScrollAxes) {
onNestedScrollAccepted(child, target, nestedScrollAxes, ViewCompat.TYPE_TOUCH);
}
@Override
public void onNestedScrollAccepted(View child, View target, int nestedScrollAxes, int type) {
mNestedScrollingParentHelper.onNestedScrollAccepted(child, target, nestedScrollAxes, type);
mNestedScrollingTarget = target;
final int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
final View view = getChildAt(i);
final LayoutParams lp = (LayoutParams) view.getLayoutParams();
if (!lp.isNestedScrollAccepted(type)) {
continue;
}
final Behavior viewBehavior = lp.getBehavior();
if (viewBehavior != null) {
viewBehavior.onNestedScrollAccepted(this, view, child, target,
nestedScrollAxes, type);
}
}
}
@Override
public void onStopNestedScroll(View target) {
onStopNestedScroll(target, ViewCompat.TYPE_TOUCH);
}
@Override
public void onStopNestedScroll(View target, int type) {
mNestedScrollingParentHelper.onStopNestedScroll(target, type);
final int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
final View view = getChildAt(i);
final LayoutParams lp = (LayoutParams) view.getLayoutParams();
if (!lp.isNestedScrollAccepted(type)) {
continue;
}
final Behavior viewBehavior = lp.getBehavior();
if (viewBehavior != null) {
viewBehavior.onStopNestedScroll(this, view, target, type);
}
lp.resetNestedScroll(type);
lp.resetChangedAfterNestedScroll();
}
mNestedScrollingTarget = null;
}
@Override
public void onNestedScroll(View target, int dxConsumed, int dyConsumed,
int dxUnconsumed, int dyUnconsumed) {
onNestedScroll(target, dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed,
ViewCompat.TYPE_TOUCH);
}
@Override
public void onNestedScroll(View target, int dxConsumed, int dyConsumed,
int dxUnconsumed, int dyUnconsumed, int type) {
final int childCount = getChildCount();
boolean accepted = false;
for (int i = 0; i < childCount; i++) {
final View view = getChildAt(i);
if (view.getVisibility() == GONE) {
// If the child is GONE, skip...
continue;
}
final LayoutParams lp = (LayoutParams) view.getLayoutParams();
if (!lp.isNestedScrollAccepted(type)) {
continue;
}
final Behavior viewBehavior = lp.getBehavior();
if (viewBehavior != null) {
viewBehavior.onNestedScroll(this, view, target, dxConsumed, dyConsumed,
dxUnconsumed, dyUnconsumed, type);
accepted = true;
}
}
if (accepted) {
onChildViewsChanged(EVENT_NESTED_SCROLL);
}
}
@Override
public void onNestedPreScroll(View target, int dx, int dy, int[] consumed) {
onNestedPreScroll(target, dx, dy, consumed, ViewCompat.TYPE_TOUCH);
}
@Override
public void onNestedPreScroll(View target, int dx, int dy, int[] consumed, int type) {
int xConsumed = 0;
int yConsumed = 0;
boolean accepted = false;
final int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
final View view = getChildAt(i);
if (view.getVisibility() == GONE) {
// If the child is GONE, skip...
continue;
}
final LayoutParams lp = (LayoutParams) view.getLayoutParams();
if (!lp.isNestedScrollAccepted(type)) {
continue;
}
final Behavior viewBehavior = lp.getBehavior();
if (viewBehavior != null) {
mTempIntPair[0] = mTempIntPair[1] = 0;
viewBehavior.onNestedPreScroll(this, view, target, dx, dy, mTempIntPair, type);
xConsumed = dx > 0 ? Math.max(xConsumed, mTempIntPair[0])
: Math.min(xConsumed, mTempIntPair[0]);
yConsumed = dy > 0 ? Math.max(yConsumed, mTempIntPair[1])
: Math.min(yConsumed, mTempIntPair[1]);
accepted = true;
}
}
consumed[0] = xConsumed;
consumed[1] = yConsumed;
if (accepted) {
onChildViewsChanged(EVENT_NESTED_SCROLL);
}
}
@Override
public boolean onNestedFling(View target, float velocityX, float velocityY, boolean consumed) {
boolean handled = false;
final int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
final View view = getChildAt(i);
if (view.getVisibility() == GONE) {
// If the child is GONE, skip...
continue;
}
final LayoutParams lp = (LayoutParams) view.getLayoutParams();
if (!lp.isNestedScrollAccepted(ViewCompat.TYPE_TOUCH)) {
continue;
}
final Behavior viewBehavior = lp.getBehavior();
if (viewBehavior != null) {
handled |= viewBehavior.onNestedFling(this, view, target, velocityX, velocityY,
consumed);
}
}
if (handled) {
onChildViewsChanged(EVENT_NESTED_SCROLL);
}
return handled;
}
@Override
public boolean onNestedPreFling(View target, float velocityX, float velocityY) {
boolean handled = false;
final int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
final View view = getChildAt(i);
if (view.getVisibility() == GONE) {
// If the child is GONE, skip...
continue;
}
final LayoutParams lp = (LayoutParams) view.getLayoutParams();
if (!lp.isNestedScrollAccepted(ViewCompat.TYPE_TOUCH)) {
continue;
}
final Behavior viewBehavior = lp.getBehavior();
if (viewBehavior != null) {
handled |= viewBehavior.onNestedPreFling(this, view, target, velocityX, velocityY);
}
}
return handled;
}
@Override
public int getNestedScrollAxes() {
return mNestedScrollingParentHelper.getNestedScrollAxes();
}
class OnPreDrawListener implements ViewTreeObserver.OnPreDrawListener {
@Override
public boolean onPreDraw() {
onChildViewsChanged(EVENT_PRE_DRAW);
return true;
}
}
/**
* Sorts child views with higher Z values to the beginning of a collection.
*/
static class ViewElevationComparator implements Comparator {
@Override
public int compare(View lhs, View rhs) {
final float lz = ViewCompat.getZ(lhs);
final float rz = ViewCompat.getZ(rhs);
if (lz > rz) {
return -1;
} else if (lz < rz) {
return 1;
}
return 0;
}
}
/**
* Defines the default {@link Behavior} of a {@link View} class.
*
* When writing a custom view, use this annotation to define the default behavior
* when used as a direct child of an {@link CoordinatorLayout}. The default behavior
* can be overridden using {@link LayoutParams#setBehavior}.
*
* Example: @DefaultBehavior(MyBehavior.class)
*/
@Retention(RetentionPolicy.RUNTIME)
public @interface DefaultBehavior {
Class value();
}
/**
* Interaction behavior plugin for child views of {@link CoordinatorLayout}.
*
* A Behavior implements one or more interactions that a user can take on a child view.
* These interactions may include drags, swipes, flings, or any other gestures.
*
* @param The View type that this Behavior operates on
*/
public static abstract class Behavior {
/**
* Default constructor for instantiating Behaviors.
*/
public Behavior() {
}
/**
* Default constructor for inflating Behaviors from layout. The Behavior will have
* the opportunity to parse specially defined layout parameters. These parameters will
* appear on the child view tag.
*
* @param context
* @param attrs
*/
public Behavior(Context context, AttributeSet attrs) {
}
/**
* Called when the Behavior has been attached to a LayoutParams instance.
*
* This will be called after the LayoutParams has been instantiated and can be
* modified.
*
* @param params the LayoutParams instance that this Behavior has been attached to
*/
public void onAttachedToLayoutParams(@NonNull CoordinatorLayout.LayoutParams params) {
}
/**
* Called when the Behavior has been detached from its holding LayoutParams instance.
*
* This will only be called if the Behavior has been explicitly removed from the
* LayoutParams instance via {@link LayoutParams#setBehavior(Behavior)}. It will not be
* called if the associated view is removed from the CoordinatorLayout or similar.
*/
public void onDetachedFromLayoutParams() {
}
/**
* Respond to CoordinatorLayout touch events before they are dispatched to child views.
*
* Behaviors can use this to monitor inbound touch events until one decides to
* intercept the rest of the event stream to take an action on its associated child view.
* This method will return false until it detects the proper intercept conditions, then
* return true once those conditions have occurred.
*
* Once a Behavior intercepts touch events, the rest of the event stream will
* be sent to the {@link #onTouchEvent} method.
*
* This method will be called regardless of the visibility of the associated child
* of the behavior. If you only wish to handle touch events when the child is visible, you
* should add a check to {@link View#isShown()} on the given child.
*
* The default implementation of this method always returns false.
*
* @param parent the parent view currently receiving this touch event
* @param child the child view associated with this Behavior
* @param ev the MotionEvent describing the touch event being processed
* @return true if this Behavior would like to intercept and take over the event stream.
* The default always returns false.
*/
public boolean onInterceptTouchEvent(CoordinatorLayout parent, V child, MotionEvent ev) {
return false;
}
/**
* Respond to CoordinatorLayout touch events after this Behavior has started
* {@link #onInterceptTouchEvent intercepting} them.
*
* Behaviors may intercept touch events in order to help the CoordinatorLayout
* manipulate its child views. For example, a Behavior may allow a user to drag a
* UI pane open or closed. This method should perform actual mutations of view
* layout state.
*
* This method will be called regardless of the visibility of the associated child
* of the behavior. If you only wish to handle touch events when the child is visible, you
* should add a check to {@link View#isShown()} on the given child.
*
* @param parent the parent view currently receiving this touch event
* @param child the child view associated with this Behavior
* @param ev the MotionEvent describing the touch event being processed
* @return true if this Behavior handled this touch event and would like to continue
* receiving events in this stream. The default always returns false.
*/
public boolean onTouchEvent(CoordinatorLayout parent, V child, MotionEvent ev) {
return false;
}
/**
* Supply a scrim color that will be painted behind the associated child view.
*
* A scrim may be used to indicate that the other elements beneath it are not currently
* interactive or actionable, drawing user focus and attention to the views above the scrim.
*
*
* The default implementation returns {@link Color#BLACK}.
*
* @param parent the parent view of the given child
* @param child the child view above the scrim
* @return the desired scrim color in 0xAARRGGBB format. The default return value is
* {@link Color#BLACK}.
* @see #getScrimOpacity(CoordinatorLayout, android.view.View)
*/
@ColorInt
public int getScrimColor(CoordinatorLayout parent, V child) {
return Color.BLACK;
}
/**
* Determine the current opacity of the scrim behind a given child view
*
* A scrim may be used to indicate that the other elements beneath it are not currently
* interactive or actionable, drawing user focus and attention to the views above the scrim.
*
*
* The default implementation returns 0.0f.
*
* @param parent the parent view of the given child
* @param child the child view above the scrim
* @return the desired scrim opacity from 0.0f to 1.0f. The default return value is 0.0f.
*/
@FloatRange(from = 0, to = 1)
public float getScrimOpacity(CoordinatorLayout parent, V child) {
return 0.f;
}
/**
* Determine whether interaction with views behind the given child in the child order
* should be blocked.
*
* The default implementation returns true if
* {@link #getScrimOpacity(CoordinatorLayout, android.view.View)} would return > 0.0f.
*
* @param parent the parent view of the given child
* @param child the child view to test
* @return true if {@link #getScrimOpacity(CoordinatorLayout, android.view.View)} would
* return > 0.0f.
*/
public boolean blocksInteractionBelow(CoordinatorLayout parent, V child) {
return getScrimOpacity(parent, child) > 0.f;
}
/**
* Determine whether the supplied child view has another specific sibling view as a
* layout dependency.
*
* This method will be called at least once in response to a layout request. If it
* returns true for a given child and dependency view pair, the parent CoordinatorLayout
* will:
*
* - Always lay out this child after the dependent child is laid out, regardless
* of child order.
* - Call {@link #onDependentViewChanged} when the dependency view's layout or
* position changes.
*
*
* @param parent the parent view of the given child
* @param child the child view to test
* @param dependency the proposed dependency of child
* @return true if child's layout depends on the proposed dependency's layout,
* false otherwise
*
* @see #onDependentViewChanged(CoordinatorLayout, android.view.View, android.view.View)
*/
public boolean layoutDependsOn(CoordinatorLayout parent, V child, View dependency) {
return false;
}
/**
* Respond to a change in a child's dependent view
*
* This method is called whenever a dependent view changes in size or position outside
* of the standard layout flow. A Behavior may use this method to appropriately update
* the child view in response.
*
* A view's dependency is determined by
* {@link #layoutDependsOn(CoordinatorLayout, android.view.View, android.view.View)} or
* if {@code child} has set another view as it's anchor.
*
* Note that if a Behavior changes the layout of a child via this method, it should
* also be able to reconstruct the correct position in
* {@link #onLayoutChild(CoordinatorLayout, android.view.View, int) onLayoutChild}.
* onDependentViewChanged will not be called during normal layout since
* the layout of each child view will always happen in dependency order.
*
* If the Behavior changes the child view's size or position, it should return true.
* The default implementation returns false.
*
* @param parent the parent view of the given child
* @param child the child view to manipulate
* @param dependency the dependent view that changed
* @return true if the Behavior changed the child view's size or position, false otherwise
*/
public boolean onDependentViewChanged(CoordinatorLayout parent, V child, View dependency) {
return false;
}
/**
* Respond to a child's dependent view being removed.
*
* This method is called after a dependent view has been removed from the parent.
* A Behavior may use this method to appropriately update the child view in response.
*
* A view's dependency is determined by
* {@link #layoutDependsOn(CoordinatorLayout, android.view.View, android.view.View)} or
* if {@code child} has set another view as it's anchor.
*
* @param parent the parent view of the given child
* @param child the child view to manipulate
* @param dependency the dependent view that has been removed
*/
public void onDependentViewRemoved(CoordinatorLayout parent, V child, View dependency) {
}
/**
* Called when the parent CoordinatorLayout is about to measure the given child view.
*
* This method can be used to perform custom or modified measurement of a child view
* in place of the default child measurement behavior. The Behavior's implementation
* can delegate to the standard CoordinatorLayout measurement behavior by calling
* {@link CoordinatorLayout#onMeasureChild(android.view.View, int, int, int, int)
* parent.onMeasureChild}.
*
* @param parent the parent CoordinatorLayout
* @param child the child to measure
* @param parentWidthMeasureSpec the width requirements for this view
* @param widthUsed extra space that has been used up by the parent
* horizontally (possibly by other children of the parent)
* @param parentHeightMeasureSpec the height requirements for this view
* @param heightUsed extra space that has been used up by the parent
* vertically (possibly by other children of the parent)
* @return true if the Behavior measured the child view, false if the CoordinatorLayout
* should perform its default measurement
*/
public boolean onMeasureChild(CoordinatorLayout parent, V child,
int parentWidthMeasureSpec, int widthUsed,
int parentHeightMeasureSpec, int heightUsed) {
return false;
}
/**
* Called when the parent CoordinatorLayout is about the lay out the given child view.
*
* This method can be used to perform custom or modified layout of a child view
* in place of the default child layout behavior. The Behavior's implementation can
* delegate to the standard CoordinatorLayout measurement behavior by calling
* {@link CoordinatorLayout#onLayoutChild(android.view.View, int)
* parent.onLayoutChild}.
*
* If a Behavior implements
* {@link #onDependentViewChanged(CoordinatorLayout, android.view.View, android.view.View)}
* to change the position of a view in response to a dependent view changing, it
* should also implement onLayoutChild in such a way that respects those
* dependent views. onLayoutChild will always be called for a dependent view
* after its dependency has been laid out.
*
* @param parent the parent CoordinatorLayout
* @param child child view to lay out
* @param layoutDirection the resolved layout direction for the CoordinatorLayout, such as
* {@link ViewCompat#LAYOUT_DIRECTION_LTR} or
* {@link ViewCompat#LAYOUT_DIRECTION_RTL}.
* @return true if the Behavior performed layout of the child view, false to request
* default layout behavior
*/
public boolean onLayoutChild(CoordinatorLayout parent, V child, int layoutDirection) {
return false;
}
// Utility methods for accessing child-specific, behavior-modifiable properties.
/**
* Associate a Behavior-specific tag object with the given child view.
* This object will be stored with the child view's LayoutParams.
*
* @param child child view to set tag with
* @param tag tag object to set
*/
public static void setTag(View child, Object tag) {
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
lp.mBehaviorTag = tag;
}
/**
* Get the behavior-specific tag object with the given child view.
* This object is stored with the child view's LayoutParams.
*
* @param child child view to get tag with
* @return the previously stored tag object
*/
public static Object getTag(View child) {
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
return lp.mBehaviorTag;
}
/**
* @deprecated You should now override
* {@link #onStartNestedScroll(CoordinatorLayout, View, View, View, int, int)}. This
* method will still continue to be called if the type is {@link ViewCompat#TYPE_TOUCH}.
*/
@Deprecated
public boolean onStartNestedScroll(@NonNull CoordinatorLayout coordinatorLayout,
@NonNull V child, @NonNull View directTargetChild, @NonNull View target,
@ScrollAxis int axes) {
return false;
}
/**
* Called when a descendant of the CoordinatorLayout attempts to initiate a nested scroll.
*
* Any Behavior associated with any direct child of the CoordinatorLayout may respond
* to this event and return true to indicate that the CoordinatorLayout should act as
* a nested scrolling parent for this scroll. Only Behaviors that return true from
* this method will receive subsequent nested scroll events.
*
* @param coordinatorLayout the CoordinatorLayout parent of the view this Behavior is
* associated with
* @param child the child view of the CoordinatorLayout this Behavior is associated with
* @param directTargetChild the child view of the CoordinatorLayout that either is or
* contains the target of the nested scroll operation
* @param target the descendant view of the CoordinatorLayout initiating the nested scroll
* @param axes the axes that this nested scroll applies to. See
* {@link ViewCompat#SCROLL_AXIS_HORIZONTAL},
* {@link ViewCompat#SCROLL_AXIS_VERTICAL}
* @param type the type of input which cause this scroll event
* @return true if the Behavior wishes to accept this nested scroll
*
* @see NestedScrollingParent2#onStartNestedScroll(View, View, int, int)
*/
public boolean onStartNestedScroll(@NonNull CoordinatorLayout coordinatorLayout,
@NonNull V child, @NonNull View directTargetChild, @NonNull View target,
@ScrollAxis int axes, @NestedScrollType int type) {
if (type == ViewCompat.TYPE_TOUCH) {
return onStartNestedScroll(coordinatorLayout, child, directTargetChild,
target, axes);
}
return false;
}
/**
* @deprecated You should now override
* {@link #onNestedScrollAccepted(CoordinatorLayout, View, View, View, int, int)}. This
* method will still continue to be called if the type is {@link ViewCompat#TYPE_TOUCH}.
*/
@Deprecated
public void onNestedScrollAccepted(@NonNull CoordinatorLayout coordinatorLayout,
@NonNull V child, @NonNull View directTargetChild, @NonNull View target,
@ScrollAxis int axes) {
// Do nothing
}
/**
* Called when a nested scroll has been accepted by the CoordinatorLayout.
*
* Any Behavior associated with any direct child of the CoordinatorLayout may elect
* to accept the nested scroll as part of {@link #onStartNestedScroll}. Each Behavior
* that returned true will receive subsequent nested scroll events for that nested scroll.
*
*
* @param coordinatorLayout the CoordinatorLayout parent of the view this Behavior is
* associated with
* @param child the child view of the CoordinatorLayout this Behavior is associated with
* @param directTargetChild the child view of the CoordinatorLayout that either is or
* contains the target of the nested scroll operation
* @param target the descendant view of the CoordinatorLayout initiating the nested scroll
* @param axes the axes that this nested scroll applies to. See
* {@link ViewCompat#SCROLL_AXIS_HORIZONTAL},
* {@link ViewCompat#SCROLL_AXIS_VERTICAL}
* @param type the type of input which cause this scroll event
*
* @see NestedScrollingParent2#onNestedScrollAccepted(View, View, int, int)
*/
public void onNestedScrollAccepted(@NonNull CoordinatorLayout coordinatorLayout,
@NonNull V child, @NonNull View directTargetChild, @NonNull View target,
@ScrollAxis int axes, @NestedScrollType int type) {
if (type == ViewCompat.TYPE_TOUCH) {
onNestedScrollAccepted(coordinatorLayout, child, directTargetChild,
target, axes);
}
}
/**
* @deprecated You should now override
* {@link #onStopNestedScroll(CoordinatorLayout, View, View, int)}. This method will still
* continue to be called if the type is {@link ViewCompat#TYPE_TOUCH}.
*/
@Deprecated
public void onStopNestedScroll(@NonNull CoordinatorLayout coordinatorLayout,
@NonNull V child, @NonNull View target) {
// Do nothing
}
/**
* Called when a nested scroll has ended.
*
* Any Behavior associated with any direct child of the CoordinatorLayout may elect
* to accept the nested scroll as part of {@link #onStartNestedScroll}. Each Behavior
* that returned true will receive subsequent nested scroll events for that nested scroll.
*
*
* onStopNestedScroll marks the end of a single nested scroll event
* sequence. This is a good place to clean up any state related to the nested scroll.
*
*
* @param coordinatorLayout the CoordinatorLayout parent of the view this Behavior is
* associated with
* @param child the child view of the CoordinatorLayout this Behavior is associated with
* @param target the descendant view of the CoordinatorLayout that initiated
* the nested scroll
* @param type the type of input which cause this scroll event
*
* @see NestedScrollingParent2#onStopNestedScroll(View, int)
*/
public void onStopNestedScroll(@NonNull CoordinatorLayout coordinatorLayout,
@NonNull V child, @NonNull View target, @NestedScrollType int type) {
if (type == ViewCompat.TYPE_TOUCH) {
onStopNestedScroll(coordinatorLayout, child, target);
}
}
/**
* @deprecated You should now override
* {@link #onNestedScroll(CoordinatorLayout, View, View, int, int, int, int, int)}.
* This method will still continue to be called if the type is
* {@link ViewCompat#TYPE_TOUCH}.
*/
@Deprecated
public void onNestedScroll(@NonNull CoordinatorLayout coordinatorLayout, @NonNull V child,
@NonNull View target, int dxConsumed, int dyConsumed,
int dxUnconsumed, int dyUnconsumed) {
// Do nothing
}
/**
* Called when a nested scroll in progress has updated and the target has scrolled or
* attempted to scroll.
*
* Any Behavior associated with the direct child of the CoordinatorLayout may elect
* to accept the nested scroll as part of {@link #onStartNestedScroll}. Each Behavior
* that returned true will receive subsequent nested scroll events for that nested scroll.
*
*
* onNestedScroll is called each time the nested scroll is updated by the
* nested scrolling child, with both consumed and unconsumed components of the scroll
* supplied in pixels. Each Behavior responding to the nested scroll will receive the
* same values.
*
*
* @param coordinatorLayout the CoordinatorLayout parent of the view this Behavior is
* associated with
* @param child the child view of the CoordinatorLayout this Behavior is associated with
* @param target the descendant view of the CoordinatorLayout performing the nested scroll
* @param dxConsumed horizontal pixels consumed by the target's own scrolling operation
* @param dyConsumed vertical pixels consumed by the target's own scrolling operation
* @param dxUnconsumed horizontal pixels not consumed by the target's own scrolling
* operation, but requested by the user
* @param dyUnconsumed vertical pixels not consumed by the target's own scrolling operation,
* but requested by the user
* @param type the type of input which cause this scroll event
*
* @see NestedScrollingParent2#onNestedScroll(View, int, int, int, int, int)
*/
public void onNestedScroll(@NonNull CoordinatorLayout coordinatorLayout, @NonNull V child,
@NonNull View target, int dxConsumed, int dyConsumed,
int dxUnconsumed, int dyUnconsumed, @NestedScrollType int type) {
if (type == ViewCompat.TYPE_TOUCH) {
onNestedScroll(coordinatorLayout, child, target, dxConsumed, dyConsumed,
dxUnconsumed, dyUnconsumed);
}
}
/**
* @deprecated You should now override
* {@link #onNestedPreScroll(CoordinatorLayout, View, View, int, int, int[], int)}.
* This method will still continue to be called if the type is
* {@link ViewCompat#TYPE_TOUCH}.
*/
@Deprecated
public void onNestedPreScroll(@NonNull CoordinatorLayout coordinatorLayout,
@NonNull V child, @NonNull View target, int dx, int dy, @NonNull int[] consumed) {
// Do nothing
}
/**
* Called when a nested scroll in progress is about to update, before the target has
* consumed any of the scrolled distance.
*
* Any Behavior associated with the direct child of the CoordinatorLayout may elect
* to accept the nested scroll as part of {@link #onStartNestedScroll}. Each Behavior
* that returned true will receive subsequent nested scroll events for that nested scroll.
*
*
* onNestedPreScroll is called each time the nested scroll is updated
* by the nested scrolling child, before the nested scrolling child has consumed the scroll
* distance itself. Each Behavior responding to the nested scroll will receive the
* same values. The CoordinatorLayout will report as consumed the maximum number
* of pixels in either direction that any Behavior responding to the nested scroll reported
* as consumed.
*
* @param coordinatorLayout the CoordinatorLayout parent of the view this Behavior is
* associated with
* @param child the child view of the CoordinatorLayout this Behavior is associated with
* @param target the descendant view of the CoordinatorLayout performing the nested scroll
* @param dx the raw horizontal number of pixels that the user attempted to scroll
* @param dy the raw vertical number of pixels that the user attempted to scroll
* @param consumed out parameter. consumed[0] should be set to the distance of dx that
* was consumed, consumed[1] should be set to the distance of dy that
* was consumed
* @param type the type of input which cause this scroll event
*
* @see NestedScrollingParent2#onNestedPreScroll(View, int, int, int[], int)
*/
public void onNestedPreScroll(@NonNull CoordinatorLayout coordinatorLayout,
@NonNull V child, @NonNull View target, int dx, int dy, @NonNull int[] consumed,
@NestedScrollType int type) {
if (type == ViewCompat.TYPE_TOUCH) {
onNestedPreScroll(coordinatorLayout, child, target, dx, dy, consumed);
}
}
/**
* Called when a nested scrolling child is starting a fling or an action that would
* be a fling.
*
* Any Behavior associated with the direct child of the CoordinatorLayout may elect
* to accept the nested scroll as part of {@link #onStartNestedScroll}. Each Behavior
* that returned true will receive subsequent nested scroll events for that nested scroll.
*
*
* onNestedFling is called when the current nested scrolling child view
* detects the proper conditions for a fling. It reports if the child itself consumed
* the fling. If it did not, the child is expected to show some sort of overscroll
* indication. This method should return true if it consumes the fling, so that a child
* that did not itself take an action in response can choose not to show an overfling
* indication.
*
* @param coordinatorLayout the CoordinatorLayout parent of the view this Behavior is
* associated with
* @param child the child view of the CoordinatorLayout this Behavior is associated with
* @param target the descendant view of the CoordinatorLayout performing the nested scroll
* @param velocityX horizontal velocity of the attempted fling
* @param velocityY vertical velocity of the attempted fling
* @param consumed true if the nested child view consumed the fling
* @return true if the Behavior consumed the fling
*
* @see NestedScrollingParent#onNestedFling(View, float, float, boolean)
*/
public boolean onNestedFling(@NonNull CoordinatorLayout coordinatorLayout,
@NonNull V child, @NonNull View target, float velocityX, float velocityY,
boolean consumed) {
return false;
}
/**
* Called when a nested scrolling child is about to start a fling.
*
* Any Behavior associated with the direct child of the CoordinatorLayout may elect
* to accept the nested scroll as part of {@link #onStartNestedScroll}. Each Behavior
* that returned true will receive subsequent nested scroll events for that nested scroll.
*
*
* onNestedPreFling is called when the current nested scrolling child view
* detects the proper conditions for a fling, but it has not acted on it yet. A
* Behavior can return true to indicate that it consumed the fling. If at least one
* Behavior returns true, the fling should not be acted upon by the child.
*
* @param coordinatorLayout the CoordinatorLayout parent of the view this Behavior is
* associated with
* @param child the child view of the CoordinatorLayout this Behavior is associated with
* @param target the descendant view of the CoordinatorLayout performing the nested scroll
* @param velocityX horizontal velocity of the attempted fling
* @param velocityY vertical velocity of the attempted fling
* @return true if the Behavior consumed the fling
*
* @see NestedScrollingParent#onNestedPreFling(View, float, float)
*/
public boolean onNestedPreFling(@NonNull CoordinatorLayout coordinatorLayout,
@NonNull V child, @NonNull View target, float velocityX, float velocityY) {
return false;
}
/**
* Called when the window insets have changed.
*
* Any Behavior associated with the direct child of the CoordinatorLayout may elect
* to handle the window inset change on behalf of it's associated view.
*
*
* @param coordinatorLayout the CoordinatorLayout parent of the view this Behavior is
* associated with
* @param child the child view of the CoordinatorLayout this Behavior is associated with
* @param insets the new window insets.
*
* @return The insets supplied, minus any insets that were consumed
*/
@NonNull
public WindowInsetsCompat onApplyWindowInsets(CoordinatorLayout coordinatorLayout,
V child, WindowInsetsCompat insets) {
return insets;
}
/**
* Called when a child of the view associated with this behavior wants a particular
* rectangle to be positioned onto the screen.
*
* The contract for this method is the same as
* {@link ViewParent#requestChildRectangleOnScreen(View, Rect, boolean)}.
*
* @param coordinatorLayout the CoordinatorLayout parent of the view this Behavior is
* associated with
* @param child the child view of the CoordinatorLayout this Behavior is
* associated with
* @param rectangle The rectangle which the child wishes to be on the screen
* in the child's coordinates
* @param immediate true to forbid animated or delayed scrolling, false otherwise
* @return true if the Behavior handled the request
* @see ViewParent#requestChildRectangleOnScreen(View, Rect, boolean)
*/
public boolean onRequestChildRectangleOnScreen(CoordinatorLayout coordinatorLayout,
V child, Rect rectangle, boolean immediate) {
return false;
}
/**
* Hook allowing a behavior to re-apply a representation of its internal state that had
* previously been generated by {@link #onSaveInstanceState}. This function will never
* be called with a null state.
*
* @param parent the parent CoordinatorLayout
* @param child child view to restore from
* @param state The frozen state that had previously been returned by
* {@link #onSaveInstanceState}.
*
* @see #onSaveInstanceState()
*/
public void onRestoreInstanceState(CoordinatorLayout parent, V child, Parcelable state) {
// no-op
}
/**
* Hook allowing a behavior to generate a representation of its internal state
* that can later be used to create a new instance with that same state.
* This state should only contain information that is not persistent or can
* not be reconstructed later.
*
* Behavior state is only saved when both the parent {@link CoordinatorLayout} and
* a view using this behavior have valid IDs set.
*
* @param parent the parent CoordinatorLayout
* @param child child view to restore from
*
* @return Returns a Parcelable object containing the behavior's current dynamic
* state.
*
* @see #onRestoreInstanceState(android.os.Parcelable)
* @see View#onSaveInstanceState()
*/
public Parcelable onSaveInstanceState(CoordinatorLayout parent, V child) {
return BaseSavedState.EMPTY_STATE;
}
/**
* Called when a view is set to dodge view insets.
*
* This method allows a behavior to update the rectangle that should be dodged.
* The rectangle should be in the parent's coordinate system and within the child's
* bounds. If not, a {@link IllegalArgumentException} is thrown.
*
* @param parent the CoordinatorLayout parent of the view this Behavior is
* associated with
* @param child the child view of the CoordinatorLayout this Behavior is associated with
* @param rect the rect to update with the dodge rectangle
* @return true the rect was updated, false if we should use the child's bounds
*/
public boolean getInsetDodgeRect(@NonNull CoordinatorLayout parent, @NonNull V child,
@NonNull Rect rect) {
return false;
}
}
/**
* Parameters describing the desired layout for a child of a {@link CoordinatorLayout}.
*/
public static class LayoutParams extends ViewGroup.MarginLayoutParams {
/**
* A {@link Behavior} that the child view should obey.
*/
Behavior mBehavior;
boolean mBehaviorResolved = false;
/**
* A {@link Gravity} value describing how this child view should lay out.
* If either or both of the axes are not specified, they are treated by CoordinatorLayout
* as {@link Gravity#TOP} or {@link GravityCompat#START}. If an
* {@link #setAnchorId(int) anchor} is also specified, the gravity describes how this child
* view should be positioned relative to its anchored position.
*/
public int gravity = Gravity.NO_GRAVITY;
/**
* A {@link Gravity} value describing which edge of a child view's
* {@link #getAnchorId() anchor} view the child should position itself relative to.
*/
public int anchorGravity = Gravity.NO_GRAVITY;
/**
* The index of the horizontal keyline specified to the parent CoordinatorLayout that this
* child should align relative to. If an {@link #setAnchorId(int) anchor} is present the
* keyline will be ignored.
*/
public int keyline = -1;
/**
* A {@link View#getId() view id} of a descendant view of the CoordinatorLayout that
* this child should position relative to.
*/
int mAnchorId = View.NO_ID;
/**
* A {@link Gravity} value describing how this child view insets the CoordinatorLayout.
* Other child views which are set to dodge the same inset edges will be moved appropriately
* so that the views do not overlap.
*/
public int insetEdge = Gravity.NO_GRAVITY;
/**
* A {@link Gravity} value describing how this child view dodges any inset child views in
* the CoordinatorLayout. Any views which are inset on the same edge as this view is set to
* dodge will result in this view being moved so that the views do not overlap.
*/
public int dodgeInsetEdges = Gravity.NO_GRAVITY;
int mInsetOffsetX;
int mInsetOffsetY;
View mAnchorView;
View mAnchorDirectChild;
private boolean mDidBlockInteraction;
private boolean mDidAcceptNestedScrollTouch;
private boolean mDidAcceptNestedScrollNonTouch;
private boolean mDidChangeAfterNestedScroll;
final Rect mLastChildRect = new Rect();
Object mBehaviorTag;
public LayoutParams(int width, int height) {
super(width, height);
}
LayoutParams(Context context, AttributeSet attrs) {
super(context, attrs);
final TypedArray a = context.obtainStyledAttributes(attrs,
R.styleable.CoordinatorLayout_Layout);
this.gravity = a.getInteger(
R.styleable.CoordinatorLayout_Layout_android_layout_gravity,
Gravity.NO_GRAVITY);
mAnchorId = a.getResourceId(R.styleable.CoordinatorLayout_Layout_layout_anchor,
View.NO_ID);
this.anchorGravity = a.getInteger(
R.styleable.CoordinatorLayout_Layout_layout_anchorGravity,
Gravity.NO_GRAVITY);
this.keyline = a.getInteger(R.styleable.CoordinatorLayout_Layout_layout_keyline,
-1);
insetEdge = a.getInt(R.styleable.CoordinatorLayout_Layout_layout_insetEdge, 0);
dodgeInsetEdges = a.getInt(
R.styleable.CoordinatorLayout_Layout_layout_dodgeInsetEdges, 0);
mBehaviorResolved = a.hasValue(
R.styleable.CoordinatorLayout_Layout_layout_behavior);
if (mBehaviorResolved) {
mBehavior = parseBehavior(context, attrs, a.getString(
R.styleable.CoordinatorLayout_Layout_layout_behavior));
}
a.recycle();
if (mBehavior != null) {
// If we have a Behavior, dispatch that it has been attached
mBehavior.onAttachedToLayoutParams(this);
}
}
public LayoutParams(LayoutParams p) {
super(p);
}
public LayoutParams(MarginLayoutParams p) {
super(p);
}
public LayoutParams(ViewGroup.LayoutParams p) {
super(p);
}
/**
* Get the id of this view's anchor.
*
* @return A {@link View#getId() view id} or {@link View#NO_ID} if there is no anchor
*/
@IdRes
public int getAnchorId() {
return mAnchorId;
}
/**
* Set the id of this view's anchor.
*
* The view with this id must be a descendant of the CoordinatorLayout containing
* the child view this LayoutParams belongs to. It may not be the child view with
* this LayoutParams or a descendant of it.
*
* @param id The {@link View#getId() view id} of the anchor or
* {@link View#NO_ID} if there is no anchor
*/
public void setAnchorId(@IdRes int id) {
invalidateAnchor();
mAnchorId = id;
}
/**
* Get the behavior governing the layout and interaction of the child view within
* a parent CoordinatorLayout.
*
* @return The current behavior or null if no behavior is specified
*/
@Nullable
public Behavior getBehavior() {
return mBehavior;
}
/**
* Set the behavior governing the layout and interaction of the child view within
* a parent CoordinatorLayout.
*
* Setting a new behavior will remove any currently associated
* {@link Behavior#setTag(android.view.View, Object) Behavior tag}.
*
* @param behavior The behavior to set or null for no special behavior
*/
public void setBehavior(@Nullable Behavior behavior) {
if (mBehavior != behavior) {
if (mBehavior != null) {
// First detach any old behavior
mBehavior.onDetachedFromLayoutParams();
}
mBehavior = behavior;
mBehaviorTag = null;
mBehaviorResolved = true;
if (behavior != null) {
// Now dispatch that the Behavior has been attached
behavior.onAttachedToLayoutParams(this);
}
}
}
/**
* Set the last known position rect for this child view
* @param r the rect to set
*/
void setLastChildRect(Rect r) {
mLastChildRect.set(r);
}
/**
* Get the last known position rect for this child view.
* Note: do not mutate the result of this call.
*/
Rect getLastChildRect() {
return mLastChildRect;
}
/**
* Returns true if the anchor id changed to another valid view id since the anchor view
* was resolved.
*/
boolean checkAnchorChanged() {
return mAnchorView == null && mAnchorId != View.NO_ID;
}
/**
* Returns true if the associated Behavior previously blocked interaction with other views
* below the associated child since the touch behavior tracking was last
* {@link #resetTouchBehaviorTracking() reset}.
*
* @see #isBlockingInteractionBelow(CoordinatorLayout, android.view.View)
*/
boolean didBlockInteraction() {
if (mBehavior == null) {
mDidBlockInteraction = false;
}
return mDidBlockInteraction;
}
/**
* Check if the associated Behavior wants to block interaction below the given child
* view. The given child view should be the child this LayoutParams is associated with.
*
* Once interaction is blocked, it will remain blocked until touch interaction tracking
* is {@link #resetTouchBehaviorTracking() reset}.
*
* @param parent the parent CoordinatorLayout
* @param child the child view this LayoutParams is associated with
* @return true to block interaction below the given child
*/
boolean isBlockingInteractionBelow(CoordinatorLayout parent, View child) {
if (mDidBlockInteraction) {
return true;
}
return mDidBlockInteraction |= mBehavior != null
? mBehavior.blocksInteractionBelow(parent, child)
: false;
}
/**
* Reset tracking of Behavior-specific touch interactions. This includes
* interaction blocking.
*
* @see #isBlockingInteractionBelow(CoordinatorLayout, android.view.View)
* @see #didBlockInteraction()
*/
void resetTouchBehaviorTracking() {
mDidBlockInteraction = false;
}
void resetNestedScroll(int type) {
setNestedScrollAccepted(type, false);
}
void setNestedScrollAccepted(int type, boolean accept) {
switch (type) {
case ViewCompat.TYPE_TOUCH:
mDidAcceptNestedScrollTouch = accept;
break;
case ViewCompat.TYPE_NON_TOUCH:
mDidAcceptNestedScrollNonTouch = accept;
break;
}
}
boolean isNestedScrollAccepted(int type) {
switch (type) {
case ViewCompat.TYPE_TOUCH:
return mDidAcceptNestedScrollTouch;
case ViewCompat.TYPE_NON_TOUCH:
return mDidAcceptNestedScrollNonTouch;
}
return false;
}
boolean getChangedAfterNestedScroll() {
return mDidChangeAfterNestedScroll;
}
void setChangedAfterNestedScroll(boolean changed) {
mDidChangeAfterNestedScroll = changed;
}
void resetChangedAfterNestedScroll() {
mDidChangeAfterNestedScroll = false;
}
/**
* Check if an associated child view depends on another child view of the CoordinatorLayout.
*
* @param parent the parent CoordinatorLayout
* @param child the child to check
* @param dependency the proposed dependency to check
* @return true if child depends on dependency
*/
boolean dependsOn(CoordinatorLayout parent, View child, View dependency) {
return dependency == mAnchorDirectChild
|| shouldDodge(dependency, ViewCompat.getLayoutDirection(parent))
|| (mBehavior != null && mBehavior.layoutDependsOn(parent, child, dependency));
}
/**
* Invalidate the cached anchor view and direct child ancestor of that anchor.
* The anchor will need to be
* {@link #findAnchorView(CoordinatorLayout, android.view.View) found} before
* being used again.
*/
void invalidateAnchor() {
mAnchorView = mAnchorDirectChild = null;
}
/**
* Locate the appropriate anchor view by the current {@link #setAnchorId(int) anchor id}
* or return the cached anchor view if already known.
*
* @param parent the parent CoordinatorLayout
* @param forChild the child this LayoutParams is associated with
* @return the located descendant anchor view, or null if the anchor id is
* {@link View#NO_ID}.
*/
View findAnchorView(CoordinatorLayout parent, View forChild) {
if (mAnchorId == View.NO_ID) {
mAnchorView = mAnchorDirectChild = null;
return null;
}
if (mAnchorView == null || !verifyAnchorView(forChild, parent)) {
resolveAnchorView(forChild, parent);
}
return mAnchorView;
}
/**
* Determine the anchor view for the child view this LayoutParams is assigned to.
* Assumes mAnchorId is valid.
*/
private void resolveAnchorView(final View forChild, final CoordinatorLayout parent) {
mAnchorView = parent.findViewById(mAnchorId);
if (mAnchorView != null) {
if (mAnchorView == parent) {
if (parent.isInEditMode()) {
mAnchorView = mAnchorDirectChild = null;
return;
}
throw new IllegalStateException(
"View can not be anchored to the the parent CoordinatorLayout");
}
View directChild = mAnchorView;
for (ViewParent p = mAnchorView.getParent();
p != parent && p != null;
p = p.getParent()) {
if (p == forChild) {
if (parent.isInEditMode()) {
mAnchorView = mAnchorDirectChild = null;
return;
}
throw new IllegalStateException(
"Anchor must not be a descendant of the anchored view");
}
if (p instanceof View) {
directChild = (View) p;
}
}
mAnchorDirectChild = directChild;
} else {
if (parent.isInEditMode()) {
mAnchorView = mAnchorDirectChild = null;
return;
}
throw new IllegalStateException("Could not find CoordinatorLayout descendant view"
+ " with id " + parent.getResources().getResourceName(mAnchorId)
+ " to anchor view " + forChild);
}
}
/**
* Verify that the previously resolved anchor view is still valid - that it is still
* a descendant of the expected parent view, it is not the child this LayoutParams
* is assigned to or a descendant of it, and it has the expected id.
*/
private boolean verifyAnchorView(View forChild, CoordinatorLayout parent) {
if (mAnchorView.getId() != mAnchorId) {
return false;
}
View directChild = mAnchorView;
for (ViewParent p = mAnchorView.getParent();
p != parent;
p = p.getParent()) {
if (p == null || p == forChild) {
mAnchorView = mAnchorDirectChild = null;
return false;
}
if (p instanceof View) {
directChild = (View) p;
}
}
mAnchorDirectChild = directChild;
return true;
}
/**
* Checks whether the view with this LayoutParams should dodge the specified view.
*/
private boolean shouldDodge(View other, int layoutDirection) {
LayoutParams lp = (LayoutParams) other.getLayoutParams();
final int absInset = GravityCompat.getAbsoluteGravity(lp.insetEdge, layoutDirection);
return absInset != Gravity.NO_GRAVITY && (absInset &
GravityCompat.getAbsoluteGravity(dodgeInsetEdges, layoutDirection)) == absInset;
}
}
private class HierarchyChangeListener implements OnHierarchyChangeListener {
HierarchyChangeListener() {
}
@Override
public void onChildViewAdded(View parent, View child) {
if (mOnHierarchyChangeListener != null) {
mOnHierarchyChangeListener.onChildViewAdded(parent, child);
}
}
@Override
public void onChildViewRemoved(View parent, View child) {
onChildViewsChanged(EVENT_VIEW_REMOVED);
if (mOnHierarchyChangeListener != null) {
mOnHierarchyChangeListener.onChildViewRemoved(parent, child);
}
}
}
@Override
protected void onRestoreInstanceState(Parcelable state) {
if (!(state instanceof SavedState)) {
super.onRestoreInstanceState(state);
return;
}
final SavedState ss = (SavedState) state;
super.onRestoreInstanceState(ss.getSuperState());
final SparseArray behaviorStates = ss.behaviorStates;
for (int i = 0, count = getChildCount(); i < count; i++) {
final View child = getChildAt(i);
final int childId = child.getId();
final LayoutParams lp = getResolvedLayoutParams(child);
final Behavior b = lp.getBehavior();
if (childId != NO_ID && b != null) {
Parcelable savedState = behaviorStates.get(childId);
if (savedState != null) {
b.onRestoreInstanceState(this, child, savedState);
}
}
}
}
@Override
protected Parcelable onSaveInstanceState() {
final SavedState ss = new SavedState(super.onSaveInstanceState());
final SparseArray behaviorStates = new SparseArray<>();
for (int i = 0, count = getChildCount(); i < count; i++) {
final View child = getChildAt(i);
final int childId = child.getId();
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
final Behavior b = lp.getBehavior();
if (childId != NO_ID && b != null) {
// If the child has an ID and a Behavior, let it save some state...
Parcelable state = b.onSaveInstanceState(this, child);
if (state != null) {
behaviorStates.append(childId, state);
}
}
}
ss.behaviorStates = behaviorStates;
return ss;
}
@Override
public boolean requestChildRectangleOnScreen(View child, Rect rectangle, boolean immediate) {
final CoordinatorLayout.LayoutParams lp = (LayoutParams) child.getLayoutParams();
final Behavior behavior = lp.getBehavior();
if (behavior != null
&& behavior.onRequestChildRectangleOnScreen(this, child, rectangle, immediate)) {
return true;
}
return super.requestChildRectangleOnScreen(child, rectangle, immediate);
}
private void setupForInsets() {
if (Build.VERSION.SDK_INT < 21) {
return;
}
if (ViewCompat.getFitsSystemWindows(this)) {
if (mApplyWindowInsetsListener == null) {
mApplyWindowInsetsListener =
new android.support.v4.view.OnApplyWindowInsetsListener() {
@Override
public WindowInsetsCompat onApplyWindowInsets(View v,
WindowInsetsCompat insets) {
return setWindowInsets(insets);
}
};
}
// First apply the insets listener
ViewCompat.setOnApplyWindowInsetsListener(this, mApplyWindowInsetsListener);
// Now set the sys ui flags to enable us to lay out in the window insets
setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_STABLE
| View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN);
} else {
ViewCompat.setOnApplyWindowInsetsListener(this, null);
}
}
protected static class SavedState extends AbsSavedState {
SparseArray behaviorStates;
public SavedState(Parcel source, ClassLoader loader) {
super(source, loader);
final int size = source.readInt();
final int[] ids = new int[size];
source.readIntArray(ids);
final Parcelable[] states = source.readParcelableArray(loader);
behaviorStates = new SparseArray<>(size);
for (int i = 0; i < size; i++) {
behaviorStates.append(ids[i], states[i]);
}
}
public SavedState(Parcelable superState) {
super(superState);
}
@Override
public void writeToParcel(Parcel dest, int flags) {
super.writeToParcel(dest, flags);
final int size = behaviorStates != null ? behaviorStates.size() : 0;
dest.writeInt(size);
final int[] ids = new int[size];
final Parcelable[] states = new Parcelable[size];
for (int i = 0; i < size; i++) {
ids[i] = behaviorStates.keyAt(i);
states[i] = behaviorStates.valueAt(i);
}
dest.writeIntArray(ids);
dest.writeParcelableArray(states, flags);
}
public static final Parcelable.Creator CREATOR =
new ClassLoaderCreator() {
@Override
public SavedState createFromParcel(Parcel in, ClassLoader loader) {
return new SavedState(in, loader);
}
@Override
public SavedState createFromParcel(Parcel in) {
return new SavedState(in, null);
}
@Override
public SavedState[] newArray(int size) {
return new SavedState[size];
}
};
}
}